U.S. patent application number 12/008499 was filed with the patent office on 2009-07-16 for bi-directional battery charging for coupled electronic devices.
This patent application is currently assigned to Modu Ltd.. Invention is credited to Tamir Demri, Itay Sherman.
Application Number | 20090179612 12/008499 |
Document ID | / |
Family ID | 40850072 |
Filed Date | 2009-07-16 |
United States Patent
Application |
20090179612 |
Kind Code |
A1 |
Sherman; Itay ; et
al. |
July 16, 2009 |
Bi-directional battery charging for coupled electronic devices
Abstract
A system for bi-directional battery charging, including a first
electronic device, including a first rechargeable battery, for
providing power to the first electronic device, and a first battery
charger, and a second electronic device, including a second
rechargeable battery, for providing power to the second electronic
device, a second battery charger, a voltage boost that receives an
input voltage from the first rechargeable battery and is
selectively enabled to either up-convert the input voltage as input
to the second battery charger, or else to passively pass the input
voltage to the second battery charger; and a controller for
programmatically controlling the first and the second battery
chargers and the voltage boost, wherein the second electronic
device attaches to the first electronic device to operate in
combination therewith, and wherein the controller is programmed to
decide, based on the voltages of the first and the second
rechargeable batteries: (i) whether to supply power to the second
electronic device from the first or second rechargeable battery,
(ii) whether to charge the second rechargeable battery from the
first rechargeable battery, and (iii) whether to enable or disable
the voltage boost. A method is also described and claimed.
Inventors: |
Sherman; Itay; (Hod
Hasharon, IL) ; Demri; Tamir; (Herzilya, IL) |
Correspondence
Address: |
Soquel Group, LLC
P.O. Box 691
Soquel
CA
95073
US
|
Assignee: |
Modu Ltd.
Kefar Saba
IL
|
Family ID: |
40850072 |
Appl. No.: |
12/008499 |
Filed: |
January 11, 2008 |
Current U.S.
Class: |
320/103 ;
320/114; 320/162; 455/573 |
Current CPC
Class: |
H04M 1/6041 20130101;
G06F 1/1626 20130101; H04M 1/72409 20210101; G06F 1/1632 20130101;
H02J 7/342 20200101; H02J 7/0013 20130101; Y02D 30/70 20200801;
G06F 1/263 20130101 |
Class at
Publication: |
320/103 ;
320/114; 320/162; 455/573 |
International
Class: |
H02J 7/00 20060101
H02J007/00 |
Claims
1. A system for bi-directional battery charging, comprising: a
first electronic device, comprising: a first rechargeable battery,
for providing power to the first electronic device; and a first
battery charger; and a second electronic device, comprising: a
second rechargeable battery, for providing power to the second
electronic device; a second battery charger; a voltage boost that
receives an input voltage from said first rechargeable battery and
is selectively enabled to either up-convert the input voltage as
input to said second battery charger, or else to pass the input
voltage through unchanged to said second battery charger; and a
controller for programmatically controlling said first and said
second battery chargers and said voltage boost, wherein said second
electronic device attaches to said first electronic device to
operate in combination therewith, and wherein said controller is
programmed to decide, based on the voltages of said first and said
second rechargeable batteries: (i) whether to supply power to said
second electronic device from said first or second rechargeable
battery, (ii) whether to charge said second rechargeable battery
from said first rechargeable battery, and (iii) whether to enable
or disable said voltage boost.
2. The system of claim 1 wherein said second battery charger
operates in a fixed current and a fixed voltage mode, and wherein
said controller further decides (iv) whether said second battery
charger should operate in the fixed current or the fixed voltage
mode.
3. The system of claim 2 wherein said second electronic device has
a high current consumption operational mode and a standby current
consumption operational mode, and wherein said controller bases its
decisions (i)-(iv) on the operational mode of said second
electronic device.
4. The system of claim 1 wherein said second battery charger is a
dual input charger, with one input from said voltage boost and
another input from a USB charger.
5. The system of claim 1 wherein said second electronic device
comprises a modular cell phone, and said first electronic device
comprises a jacket for said modular cell phone.
6. The system of claim 1 wherein said second electronic device
comprises a modular media player, and said first electronic device
comprises a jacket for said modular media player.
7. A system for bi-directional battery charging, comprising: a
first electronic device, comprising: a first rechargeable battery,
for providing power to the first electronic device; a first battery
charger; a first voltage boost for receiving an input voltage is
selectively enabled to either up-convert the input voltage as input
to said first battery charger, or else to block the input voltage
from being transferred to said first battery charger; and a second
electronic device, comprising: a second rechargeable battery, for
providing power to the second electronic device and for providing
the input voltage to said first voltage boost; a second battery
charger; a second voltage boost that receives an input voltage from
said first rechargeable battery and is selectively enabled to
either up-convert the input voltage as input to said second battery
charger, or else to pass the input voltage through unchanged to
said second battery charger; and a controller for programmatically
controlling said first and said second battery chargers and said
first and second voltage boosts, wherein said second electronic
device attaches to said first electronic device to operate in
combination therewith, and wherein said controller is programmed to
decide, based on the voltages of said first and said second
rechargeable batteries: (i) whether to supply power to said second
electronic device from said first or said second rechargeable
battery, (ii) whether to charge said first or second rechargeable
battery from the other rechargeable battery, and (iii) whether to
enable or disable said first and second voltage boosts.
8. The system of claim 7 wherein said first and second battery
chargers operate in a fixed current and a fixed voltage mode, and
wherein said controller further decides (iv) whether said first and
said second battery chargers should operate in the fixed current or
the fixed voltage mode.
9. The system of claim 8 wherein said second electronic device has
a high current consumption operational mode and a standby current
consumption operational mode, and wherein said controller bases its
decisions (i)-(iv) on the operational mode of said second
electronic device.
10. The system of claim 7 wherein said second battery charger is a
dual input charger, with one input from said voltage boost and
another input from a USB charger.
11. The system of claim 7 wherein said second electronic device
comprises a modular cell phone, and said first electronic device
comprises a host for said modular cell phone.
12. The system of claim 7 wherein said second electronic device
comprises a modular media player, and said first electronic device
comprises a host for said modular media player.
13. A method for controlling battery power supply and battery
charging for two coupled electronic devices, each device having its
own rechargeable battery and its own internal battery charger,
comprising: determining battery voltages for each of the two
electronic devices; determining operational modes for each of the
two electronic devices; and based on said determining battery
voltages and said determining operational modes, controlling the
batteries and battery chargers comprising deciding (i) whether to
supply power to each electronic device from its own battery or from
the other device's battery, and (ii) whether to charge one battery
from the other battery.
14. The method of claim 13 wherein said controlling comprises
deciding (iii) whether to boost a voltage from one battery for
input to the other battery's charger.
15. A system for bi-directional battery charging, comprising two
coupled electronic devices, each device comprising a rechargeable
battery and an internal battery charger, wherein the rechargeable
battery of each device is able to supply power to both devices, and
wherein the rechargeable battery of each device is able to charge
the other device's rechargeable battery.
Description
FIELD OF THE INVENTION
[0001] The field of the present invention is management of battery
power supply and battery charging for electronic devices.
SUMMARY OF THE DESCRIPTION
[0002] Aspects of the present invention relate to battery supply
and battery charging of coupled electronic devices. One or both of
the electronic devices operates in a standalone mode, and the
devices also operate in a coupled mode when one is attached to the
other. Each device has its own rechargeable battery and internal
battery charger, and the coupling enables the battery of one device
to supply power to the other device, and to charge the other
device's battery. Using the present invention, optimized logic for
controlling power supply and battery charging of the coupled
devices, provides extended operational time.
[0003] The optimized logic decides when to supply battery power
from one battery to the other device, and when to charge one
battery from the other, based on the voltages of the two batteries,
and based on the operational modes of the two devices.
[0004] The present invention applies generically to a wide variety
of electronic devices that use single or dual input battery
chargers, voltage boosts, and USB chargers to power manage their
electrical components. In particular, the present invention applies
to a small modular cell phone that is attachable to host devices
and to jackets with user interfaces. The modular cell phone
provides the host devices with wireless communication
functionality, when attached thereto. The jackets provide the
modular cell phone with custom keypads, displays, microphone,
speakers and other such user interface components. The present
invention also applies to a small modular media player that
attached to host devices and provides them with media playing
functionality.
[0005] There is thus provided in accordance with an embodiment of
the present invention a system for bi-directional battery charging,
including a first electronic device, including a first rechargeable
battery, for providing power to the first electronic device, and a
first battery charger, and a second electronic device, including a
second rechargeable battery, for providing power to the second
electronic device, a second battery charger, a voltage boost that
receives an input voltage from the first rechargeable battery and
is selectively enabled to either up-convert the input voltage as
input to the second battery charger, or else to passively pass the
input voltage to the second battery charger; and a controller for
programmatically controlling the first and the second battery
chargers and the voltage boost, wherein the second electronic
device attaches to the first electronic device to operate in
combination therewith, and wherein the controller is programmed to
decide, based on the voltages of the first and the second
rechargeable batteries: (i) whether to supply power to the second
electronic device from the first or second rechargeable battery,
(ii) whether to charge the second rechargeable battery from the
first rechargeable battery, and (iii) whether to enable or disable
the voltage boost.
[0006] There is further provided in accordance with an embodiment
of the present invention a system for bi-directional battery
charging, including a first electronic device, including a first
rechargeable battery, for providing power to the first electronic
device, a first battery charger, a first voltage boost for
receiving an input voltage is selectively enabled to either
up-convert the input voltage as input to the first battery charger,
or else to block the input voltage from being transferred to the
first battery charger, and a second electronic device, including a
second rechargeable battery, for providing power to the second
electronic device and for providing the input voltage to the first
voltage boost, a second battery charger, a second voltage boost
that receives an input voltage from the first rechargeable battery
and is selectively enabled to either up-convert the input voltage
as input to the second battery charger, or else to passively pass
the input voltage to the second battery charger, and a controller
for programmatically controlling the first and the second battery
chargers and the first and second voltage boosts, wherein the
second electronic device attaches to the first electronic device to
operate in combination therewith, and wherein the controller is
programmed to decide, based on the voltages of the first and the
second rechargeable batteries: (i) whether to supply power to the
second electronic device from the first or second rechargeable
battery, (ii) whether to charge the first or second rechargeable
battery from the other rechargeable battery, and (iii) whether to
enable or disable the first and second voltage boosts.
[0007] There is yet further provided in accordance with an
embodiment of the present invention a method for controlling
battery power supply and battery charging for two coupled
electronic devices, each device having its own rechargeable battery
and its own internal battery charger, including determining battery
voltages for each of the two electronic devices, determining
operational modes for each of the two electronic devices, and based
on the determining battery voltages and the determining operational
modes, controlling the batteries and battery chargers including
deciding (i) whether to supply power to each electronic device from
its own battery or from the other device's battery, and (ii)
whether to charge one battery from the other battery.
[0008] There is additionally provided in accordance with an
embodiment of the present invention a system for bi-directional
battery charging, including two coupled electronic devices, each
device comprising a rechargeable battery and an internal battery
charger, wherein the rechargeable battery of each device is able to
supply power to both devices, and wherein the rechargeable battery
of each device is able to charge the other device's rechargeable
battery.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will be more fully understood and
appreciated from the following detailed description, taken in
conjunction with the drawings in which:
[0010] FIG. 1A is a simplified block diagram of a modular cell
phone connected to a jacket, in accordance with an embodiment of
the present invention;
[0011] FIG. 1B is a simplified block diagram of a modular cell
phone connected to a host, in accordance with an embodiment of the
present invention
[0012] FIG. 2 is a mechanical drawing with cross-sectional views of
a modular cell phone, in accordance with an embodiment of the
present invention;
[0013] FIG. 3 is an illustration of a jacket for a modular cell
phone, in accordance with an embodiment of the present
invention;
[0014] FIG. 4 is an illustration of a modular cell phone being
inserted into a jacket, in accordance with an embodiment of the
present invention;
[0015] FIG. 5 is an illustration of a modular cell phone being
inserted into a host device, in accordance with an embodiment of
the present invention;
[0016] FIG. 6 is a simplified block component diagram of a modular
cell phone, in accordance with an embodiment of the present
invention;
[0017] FIG. 7 is a simplified block component diagram of a jacket
for a modular cell phone, in accordance with an embodiment of the
present invention;
[0018] FIG. 8 is a simplified block component diagram of a host
device that interoperates with a modular cell phone, in accordance
with an embodiment of the present invention;
[0019] FIG. 9 is a simplified block diagram of bi-directional
battery charging for a jacket or a simple host device, in
accordance with an embodiment of the present invention;
[0020] FIG. 10 is a summary of bi-directional battery charging
logic for the hardware of FIG. 9, in accordance with an embodiment
of the present invention;
[0021] FIG. 11 is a simplified block diagram of bi-directional
battery charging for a complex host device, in accordance with an
embodiment of the present invention; and
[0022] FIG. 12 is a summary of bi-directional battery charging
logic for the hardware of FIG. 11, in accordance with an embodiment
of the present invention.
DETAILED DESCRIPTION
[0023] Aspects of the present invention relate to a small modular
cell phone that connects to other devices and enables the other
devices to communicate wirelessly. The modular cell phone of the
present invention operates both in standalone mode as a standalone
phone, and also in conjunction with devices to which it is
connected.
[0024] There are two general types of devices into which the
modular cell phone may be connected; namely, jackets and hosts. A
jacket is a device that provides a user interface for the modular
cell phone, and does not operate independently, when not connected
to the modular cell phone. A jacket is a device that enriches the
capabilities of the modular cell phone, and is not able to operate
independently when it is not connected to the modular cell phone.
Conversely, a host is a device that is able to operate
independently when it is not connected to the modular cell phone,
and whose capabilities are enriched by the modular cell phone when
connected thereto.
[0025] Reference is now made to FIG. 1A, which is a simplified
block diagram of a modular cell phone 100 connected to a jacket
200, in accordance with an embodiment of the present invention.
Generally, modular cell phone 100 is inserted inside jacket 200,
and connects therewith by means of a dedicated connector 400.
[0026] Reference is now made to FIG. 1B, which is a simplified
block diagram of modular cell phone 100 connected to a host 300, in
accordance with an embodiment of the present invention. Modular
cell phone 100 may be attached to host 300 or inserted therewithin,
and connects therewith by means of a dedicated connector 400.
Although FIGS. 1A and 1B appear similar at this low level of
detail, higher levels of detail in FIGS. 2-8 distinguish between
jackets and hosts.
[0027] Reference is now made to FIG. 2, which is a mechanical
drawing with cross-sectional views of modular cell phone 100, in
accordance with an embodiment of the present invention. Shown in
FIG. 2 are front, back, left side, right side and top views of
modular cell phone 100. The dimensions of modular cell phone 100
are 72.09 mm.times.37.59 mm.times.7.80 mm. It will be appreciated
by those skilled in the art that the present invention is
applicable when modular cell phone 100 is designed with other
dimensions, as well.
[0028] Reference is now made to FIG. 3, which is an illustration of
jacket 200 for a modular cell phone, in accordance with an
embodiment of the present invention. Jacket 200 shown in FIG. 3
includes a user interface for an audio/video player. Specifically,
jacket 200 includes a USB connector 240, a keypad 250, a display
255, a microphone 260 (shown in FIG. 7), speakers 265, speaker
amplifier 275 (shown in FIG. 7), an earpiece 285, an earpiece
amplifier 290 (shown in FIG. 7) and a headset audio jack 295.
[0029] It will be appreciated by those skilled in the art that the
components of jacket 200 in FIG. 3 are illustrative of one jacket
design, and that the present invention is applicable to a wide
variety of jacket designs.
[0030] Reference is now made to FIG. 4, which is an illustration of
modular cell phone 100 being inserted into jacket 200, in
accordance with an embodiment of the present invention.
[0031] Reference is now made to FIG. 5, which is an illustration of
a modular cell phone 100 being inserted into host device 300, in
accordance with an embodiment of the present invention.
[0032] Reference is now made to FIG. 6, which is a simplified block
component diagram of modular cell phone 100, in accordance with an
embodiment of the present invention. Modular cell phone 100
includes five primary components, as follows: an ASIC controller
105, a memory storage 110, a baseband modem 115 for sending and
receiving voice communications, an audio/video subsystem 120, and
cell phone charging circuitry 125 for a battery 130.
[0033] ASIC controller 105 executes programmed instructions that
control operation of mobile communication device 100. Baseband
modem 115 includes a radio frequency (RF) interface 135 that is
connected to an antenna.
[0034] Audio/video subsystem 120 includes a voice, audio and video
interface. Cell phone charging circuitry 125 includes a power
management integrated circuit. In accordance with an embodiment of
the present invention, cell phone charging circuitry 125 supports
fixed current and fixed voltage operational modes, and is capable
of measuring voltage and current. Cell phone charging circuitry 125
is controlled by controller 105.
[0035] Modular cell phone 100 includes a USB interface 140 and an
interface 145 for connector 400. Modular cell phone 100 optionally
includes a keyboard 150, a display 155 and a SIM card 160.
[0036] Modular cell phone 100 can be operated in standalone mode,
or in conjunction with jacket 200 or host 300 when it is attached
thereto.
[0037] Reference is now made to FIG. 7, which is a simplified block
component diagram of jacket 200 for modular cell phone 100, in
accordance with an embodiment of the present invention. Jacket 200
includes a controller 205, jacket charging circuitry 225 and
battery 230, and a USB connector 240. Jacket charging circuitry 225
supports both a fixed voltage mode and a fixed current mode. Jacket
charging circuitry 225 independently controls internal current and
voltage of jacket 200.
[0038] Jacket 200 provides a variety of user interface components
for modular cell phone 100, including keyboard 250, display 255,
microphone 260, respective left and right speakers and left and
right speaker amplifiers 265, 270, 275 and 280, earpiece 285 and
earpiece amplifier 290 and headset audio jack 295.
[0039] Jacket 200 supports audio and USB signals being routed to
jacket headset port 295, jacket earpiece 285, one or two jacket
speakers 265 and 270, and jacket USB connector 240. Jacket 200
supports stereo amplifiers 275 and 280, with high impedance inputs
and outputs for driving 8.OMEGA. speakers 265 and 270. The
circuitry in jacket 200 also supports earpiece amplifier 290, with
a high impedance input and output capable of driving 32.OMEGA.
speaker 285. Jacket 200 includes an external interface 245 for
connecting jacket 200 to modular cell phone 100 via connector
400.
[0040] Reference is now made to FIG. 8, which is a simplified block
component diagram of host device 300 that interoperates with
modular cell phone 100, in accordance with an embodiment of the
present invention. Host device 300 includes four interconnected
primary components; namely, a controller 305, a storage unit 310,
host charging circuitry 325 for a battery 330, and a USB interface
340. Host device 300 includes an optional audio/video subsystem
320.
[0041] Host device 300 also includes a user interface 350. User
interface 350 may include some of all of the voice, audio and video
interfaces shown in FIG. 7 with reference to jacket 200. Host
device 300 includes an external interface 345 for connecting host
device 300 to modular cell phone 100 via connector 400.
[0042] Reference is now made to FIG. 9, which is a simplified block
diagram of bi-directional battery charging for a jacket or a simple
host device, in accordance with an embodiment of the present
invention. Shown in FIG. 9 are cell phone controller 105, cell
phone charging circuitry 125 and cell phone battery 130 from FIG.
6. Charger 125 is a dual input charger. A first input is connected
to USB connector 140 for a USB charger 165, and a second input is
connected to the output of a voltage boost 170.
[0043] Also shown in FIG. 9 are jacket controller 205, jacket
charging circuitry 225, and jacket battery 230. Jacket charging
circuitry 225 is a single input charger, with its input connected
to USB connector 240 for a USB charger 265.
[0044] Connector 400 provides signals paths between components of
cell phone 100 and components of jacket 200. Via connector 400, the
input of USB charger 265, denoted by Vbus in FIG. 9, is routed to
USB charger 165.
[0045] Controller 105 is able to track the voltage on battery 230,
either by directly measuring a battery pin on connector 400, or by
receiving notifications from jacket charging circuitry 225 via
connector 400.
[0046] Voltage boost 170 receives a standard battery voltage as
input and generates as output a minimal charging voltage of cell
phone charging circuitry 125. Typical input to boost 170 is in the
range 2.7V-4.2V, and typical output is 4.7V. When enabled, boost
170 up-converts its input voltage. When disabled, boost 170 simply
passes its input voltage through to its output, minus any internal
voltage drop. Boost 170 is enabled by controller 105 via an enable
signal. The input of boost 170 is connected to a pin of connecter
400, such that when attached to jacket 200, boost 170 has a direct
connection to battery 230.
[0047] The system of FIG. 9 applies advantageously to simple
devices 200, which have limited power consumption, lower than a
threshold current, typically 500 mA. In such case, battery 130
supplies current to the electronic components of device 200 through
connector 400.
[0048] It will be appreciated by those skilled in the art that the
bi-directional battery charging diagram in FIG. 9 applies to a
general setting whereby a mobile device can be docked to an
accessory device. For the sake of clarity, the above disclosure has
been presented for a cell phone that attaches to a jacket. However,
the present invention may be used advantageously for bi-directional
battery charging for general electronic devices that include
controllers, rechargeable batteries, boosts and battery chargers as
shown in FIG. 9. To this end, the logic provided in FIG. 10
hereinbelow is disclosed in terms of a mobile standalone device and
a docked device, to address the general setting.
[0049] Reference is now made to FIG. 10, which is a summary of
bi-directional battery charging logic for the hardware of FIG. 9,
in accordance with an embodiment of the present invention. For
purposes of generality, in the notation of FIG. 10 cell phone 100
is referred to as a standalone (SA) device, and jacket 200 is
referred to as a jacket (JKT), into which the SA device can be
docked.
[0050] FIG. 10 is divided into six columns. The first column refers
to a state of the SA battery, and the second column refers to a
state of the jacket battery. Referring to FIG. 9, the following
notation is used in these two columns. [0051] CC is the charging
current for the SA battery. CC should conform to the maximal
charging current authorization set by the JKT, and is typically
between 200 mA-500 mA. For example, if the SA battery has a charge
of 500 mAh, charging with a current greater than 500 mA may be
harmful to the battery. [0052] JKT is the voltage of the JKT
battery. [0053] SA is the voltage of the SA battery. [0054] STBC is
the average standby current of the SA device. STBC is typically
between 5 mA-50 mA. [0055] Vc is the voltage drop across the SA
boost, the SA battery charger and the SA battery, when being
charged with charge CC. Vc is typically approximately 0.3V and
corresponds to 50%-100% of the SA battery capacity. [0056] Vh is
the maximal voltage to which the SA battery is charged when being
charged from the JKT battery. Vh is typically between 3.7V-4V
corresponding to approximately 50% capacity of the SA battery.
[0057] Vl is the minimal voltage for the SA battery, below which
charging from the JKT is forced. Vl is typically between 3.4V-3.5V
corresponding to approximately 10% capacity of the SA battery.
[0058] Vm is the minimal voltage for the JKT battery, below which
charging from the SA device is forced. Vm is typically between
3.4V-3.5V corresponding to approximately 10% capacity of the JKT
battery.
[0059] The third column in FIG. 10 refers to the mode in which the
SA device is operating. There are three operational modes for the
SA device, as follows: [0060] I. High Current Consumption. This
mode occurs when the SA device is active and transmitting between
the SA device and a base transceiver station (BTS). In this mode
the SA has a typical current consumption greater than 100 mA, with
peak currents possibly greater than 1 A, depending on power
requirement factors, such as the distance of the SA device from the
BTS. Using the JKT battery to supply the SA device is undesirable
in this mode, due to the high peak currents. Transfer of such high
current over connectors poses difficult requirements on the quality
and current drive of the JKT battery, boost current and charger
current, resulting in increased cost and size of the hardware.
Charging in this mode is limited to fixed current, since fixed
voltage charging draws peak currents from the JKT, which is
undesirable. [0061] II. Standby Current Consumption. This mode
occurs when the SA device is not communicating with the BTS. In
this mode the SA device has an typical current consumption less
than 100 mA, and no peak currents above 100 mA. Such current levels
are suitable for supply from the JKT battery, and do not impose
limitations on charging. [0062] III. Shutdown. In this mode the SA
device is shutdown and has negligible current consumption.
[0063] The fourth column in FIG. 10 refers to the mode of charging
the batteries. There are five charging modes, as follows: [0064] I.
No Charge. The SA battery supplies all SA current. Efficiency is
high, since no extra conversion is applied. The SA battery is being
depleted during this mode. [0065] II. Supply from JKT Battery. In
this mode, the JKT battery supplies current. Efficiency is lower
than in the No Charge mode, due to voltage drop on the SA boost and
SA charger, but in general this mode is efficient and preserves
power of the SA battery for standalone operation of the SA device.
[0066] III. Supply from SA and JKT Battery. In this mode, when
there are peaks, the current is drawn from both the SA and the JKT
battery. When there are not peaks, the current is drawn from the
JKT battery alone. Current peaks are prevalent in many wireless
communication systems, including inter alia Global System for
Mobile Communication (GSM), General Packet Radio System (GPRS),
Code Division Multiple-Access (CDMA), and Integrated Digital
Enhanced Network (IDEN). For the GSM system, peaks occur due to
time division multiplexing and are caused by time slots usage.
[0067] IV. Charge from JKT Battery. In this mode the JKT battery
charges the SA battery. This mode is inefficient, in some
circumstances possibly less than 500% efficiency. If the SA boost
is enabled, the efficiency is even lower, by approximately 100%.
When the JKT battery is empty, charging from the JKT battery is
disabled. [0068] V. Charge from SA Battery. In this mode the SA
battery charges the JKT battery. This mode is inefficient, in some
circumstances possibly less than 50% efficiency. If the JKT boost
is enabled, the efficiency is even lower, by approximately
100%.
[0069] The fifth column in FIG. 10 refers to enablement of
disablement of the SA boost. The sixth column in FIG. 10 refers to
the SA charger.
[0070] The logic in FIG. 10 is implemented as programming logic for
SA and JKT battery chargers and SA boost, to optimize their
operation. The logic in FIG. 10 prescribes columns 4-6 (charging
mode, SA boost enablement and SA charger) in terms of columns 1-3
(SA battery voltage, JKT battery voltage and SA operational mode).
For example, referring to the first two rows in FIG. 10, if
JKT>SA>Vh and if the SA device is in Standby Current
Consumption mode, then the charging mode is set for the JKT battery
to supply current to the SA device, the SA boost is disabled, and
the SA charger is set to fixed voltage level. If instead the SA
device is in High Current Consumption mode, then the charging mode
is set for both the SA and JKT battery to supply current to the SA
device, and the SA charger is set to fixed current level. The logic
in FIG. 10 optimizes usage of the SA and JKT batteries, in order to
provide extended operation time for SA device in combination with
the JKT, and in standalone mode; and in order to facilitate
charging the SA battery from JKT.
[0071] Reference is now made to FIG. 11, which is a simplified
block diagram of bi-directional battery charging for a complex host
device, in accordance with an embodiment of the present invention.
Shown in FIG. 11 are cell phone controller 105, cell phone charging
circuitry 125 and cell phone battery 130 from FIG. 6. Cell phone
charging circuitry 125 has a dual input. A first input is connected
to USB connector 140 for a USB charger 165, and a second input is
connected to the output of a voltage boost 170.
[0072] Also shown in FIG. 11 are controller 305, host charging
circuitry 325, and host battery 330. Host charging circuitry 325
has a dual input. A first input is connected to USB connector 340
for a USB charger 365, and a second input is connected to the
output of a voltage boost 370. Host charging circuitry 325 is a
hardware-based charging controller that controls charging,
including constant current charging and constant voltage charging,
based on its input voltage levels and its output HST battery
status.
[0073] Connector 400 provides signals paths between components of
cell phone 100 and components of host 300. Via connector 400, the
input of USB charger 365, denoted by Vbus in FIG. 11, is routed to
USB charger 165.
[0074] Controller 105 is able to track the voltage on battery 330,
either by directly measuring a battery pin on connector 400, or by
receiving notifications from host charging circuitry 325 via
connector 400.
[0075] Voltage boosts 170 and 370 receive standard battery voltage
as input and generate as output a minimal charging voltage of cell
phone charging circuitry 125 and host charging circuitry 325,
respectively. Typical inputs to boosts 170 and 370 are in the range
2.7V-4.2V, and typical outputs are 4.7V.
[0076] When enabled, boosts 170 and 370 up-convert their input
voltages. When disabled, boost 170 simply passes its input voltage
through to its output, minus any internal voltage drops. When
disabled, boost 370 blocks its input voltage from going out as
output.
[0077] In an alternative embodiment of the present invention, host
controller 305 enables and disables host charging circuitry 325,
and boost 370 operates similarly to boost 170; namely, when
disabled, boost 370 passes its input voltage through to its output,
minus any internal voltage drops.
[0078] Boost 170 is enabled by controller 105 via an enable signal.
The input of boost 170 is connected to a pin of connecter 400, such
that when attached to host 300, boost 170 has a direct connection
to battery 330. Similarly, boost 370 is enabled by controller 305
via an enable signal. The input of boost 370 is connected to a pin
of connector 400, such that when attached to cell phone 100, boost
370 has a direct connection to battery 130.
[0079] In yet another alternate embodiment of the present
invention, host controller 305 enables and disables host charging
circuitry 325, and boost 370 is eliminated. Instead of enabling and
disabling a voltage boost, controller 305 enables host charging
circuitry 325 when charging is desired, and disables host charging
circuitry 325 when charging is not desired.
[0080] The system of FIG. 11 applies advantageously to complex
devices 300, which have current consuming components above a
threshold current, typically 500 mA. For such devices, it is
impractical to supply their current from battery 130. Such current
would require too much draw from battery 130, and would be too high
for transfer over connector 400. Instead, battery 330 supplies
current for the components of device 300.
[0081] As mentioned above with reference to FIG. 9, it will be
appreciated by those skilled in the art that the bi-directional
battery charging diagram in FIG. 11 applies to a general setting
whereby a mobile device can be docked to an accessory device. For
the sake of clarity, the disclosure above disclosure has been
presented for a cell phone that attaches to a host. However, the
present invention may be used advantageously for bi-directional
battery charging for general electronic devices that include
controllers, rechargeable batteries, boosts and battery chargers as
shown in FIG. 11. To this end, the logic provided in FIG. 12
hereinbelow is disclosed in terms of a mobile standalone device and
a docked device, to address the general setting.
[0082] Reference is now made to FIG. 12, which is a summary of
bi-directional battery charging logic for the hardware of FIG. 11,
in accordance with an embodiment of the present invention. As with
FIG. 10, for purposes of generality, in the notation of FIG. 12
cell phone 100 is referred to as a standalone (SA) device, and host
300 is referred to as a host (HST) device, into which the SA device
can be docked. The notation indicated above for FIG. 10 applies to
FIG. 12 as well, with HST being used for the docking device instead
of JKT.
[0083] The logic in FIG. 12 is implemented as programming logic for
SA and HST battery chargers to optimize their operation. FIG. 12
uses the same six columns as FIG. 10, with an additional column for
indicating enablement/disablement of the HST charger and boost. The
logic in FIG. 12 prescribes the settings in columns 4-7 (charging
mode, SA boost enablement, SA charger, HST charger and boost) based
on the states in columns 1-3 (SA battery voltage, HST battery
voltage and SA operational mode). For example, referring to the
first two rows in FIG. 12, if HST>SA>Vh and if the SA device
is in Standby Current Consumption mode, then the charging mode is
set for the HST battery to supply current to the SA device, the SA
boost is disabled, the SA charger is set to fixed voltage level,
and the HST charger and boost are disabled. If instead the SA
device is in High Current Consumption mode, then the charging mode
is set for both the SA and HST battery to supply current to the SA
device, and the SA charger is set to fixed current level. The logic
in FIG. 12 optimizes usage of the SA and HST batteries, in order to
provide extended operation time for SA device in combination with
the HST, and in standalone mode; and in order to facilitate
charging the SA battery from the HST.
[0084] It will be appreciated by those skilled in the art that the
distinction of JKT vs HST in the systems of FIGS. 9 and 11 and in
the logic of FIGS. 10 and 12 is merely for the purpose of clarity
of exposition. The system and logic of FIGS. 9 and 10 also apply to
simple host devices 300, in addition to jackets 200; and the system
and logic of FIGS. 11 and 12 also apply to complex jackets 200, in
addition to host devices 300. In general, the system and logic of
FIGS. 9 and 10 apply to devices (jackets or hosts) with limited
power consumption; e.g., less than 500 mA; and the system and logic
of FIGS. 11 and 12 apply to devices (jackets or hosts) with higher
current consumption.
[0085] In the foregoing specification, the invention has been
described with reference to specific exemplary embodiments thereof.
It will, however, be evident that various modifications and changes
may be made to the specific exemplary embodiments without departing
from the broader spirit and scope of the invention as set forth in
the appended claims. Accordingly, the specification and drawings
are to be regarded in an illustrative rather than a restrictive
sense.
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